The chart bears the track of a Royal Navy vessel outwards from Devonport on the 28th March 1844 towards Madeira, the Canaries, Cape Verde Isles, coast of Gambia, Sierra Leone and Liberia to Cape Palmas. Then a zig-zag course to Ascension, staying for three days to resupply; off again in June to spend three weeks cruising in the Fernando Po area before returning to Ascension. Next, east to the Congo River mouth and Benguela for most on July and August, back to Ascension, finally cruising off to Angola for most of September. The Vessel is not named, but her commander has written his name, Captain Brisbane RN on the chart verso.

The track shown is that of the Royal Navy warship almost certainly patrolling the African coast in order to intercept any slave traders heading for the Caribbean or the Americas. The practice of which had been out-lawed throughout the empire in the Slavery Abolition Act 1833.

To the verso is the seller's stamp: 'Sold by W.C. Cox Optician & Co, 87 Fore Street, Davenport.

John William Norie (1772 – 1843) was a mathematician, hydrographer, chart maker and publisher of nautical books. His most famous work was the 'Epitome of Practical Navigation' (1805), which became the standard work on navigation and went through many editions. Norie began his career working with William Heather, who ran the Naval Academy and Naval Warehouse in Leadenhall Street from 1795, which sold navigational instruments, charts, and books on navigation. Norie took over the Naval Warehouse after Heather's retirement and founded the company J.W. Norie and Company in 1813. After Norie's death the company became Norie and Wilson, then in 1903 Imray, Laurie, Norie & Wilson.